J. A. Grande

A description of how metal pollution occurs in the Tinto-Odiel rias (Huelva-Spain) through the application of cluster analysis

In the last few decades, the study of space-time distribution and variations of heavy metals in estuaries has been extensively studied as an environmental indicator. In the case described here, the combination of acid water from mines, industrial effluents and sea water plays a determining role in the evolutionary process of the chemical makeup of the water in the estuary of the Tinto and Odiel Rivers, located in the southwest of the Iberian Peninsula. Based on the statistical treatment of the data from the analysis of the water samples from this system, which has been affected by processes of industrial and mining pollution, the 16 variables analyzed can be grouped into two large families. Each family presents high, positive Pearson r values that suggest common origins (fluvial or sea) for the pollutants present in the water analyzed and allow their subsequent contrast through cluster analysis.

Application of Cluster Analysis to the Geochemistry Zonation of the Estuary Waters in the Tinto and Odiel Rivers (Huelva, Spain)

The combination of acid water from mines, industrial effluents and sea water plays a determining role in the evolutionary process of the chemical makeup of the water in the estuary of the Tinto and Odiel rivers. This estuary is in the southwest of the Iberian Peninsula and is one of the estuarine systems on the northwest coast of the Gulf of Cádiz. From the statistical treatment of data obtained by analyzing samples of water from this system, which is affected by industrial and mining pollution processes, we can see how the sampling points studied form two large groups depending on whether they receive tidal or fluvial influences. Fluvial input contributes acid water with high concentrations of heavy metal, whereas industrial effluents are responsible for the presence of phosphates, silica and other nutrients. The estuarine system of the Tinto and Odiel Rivers can be divided into three areas – the Tinto estuary, the Odiel estuary and the area of confluence – based on the physical – chemical characteristics of the water.

Analysis of the Impact of Local Corrective Measures on the Input of Contaminants from the Odiel River to the Ría of Huelva (Spain)

The contamination of the Tinto and Odiel Rivers represents one ofthe most serious acid mine drainage (AMD) problems worldwide. AMDcauses two problems: the contamination of the hydrologicalnetwork and the contamination of the Ría of Huelva, an estuaryformed by the union of these two rivers. The river Odiel carriesto the estuary a large amount of chemical pollution of miningorigin with extreme pH values, sulfates and heavy metalscharacterized by monthly samples throughout a 9 year period. Inthis river, corrective measures have been carried out in 21 smallabandoned mines. In this article, a methodology is developed thatallows us to see that these measures, which have resulted inremarkable local improvement, have not had a significant effecton the contamination introduced by this river into the Ría of Huelva.

Effect of acid mine drainage on dissolved rare earth elements geochemistry along a fluvial-estuarine system: the Tinto-Odiel Estuary (S.W. Spain)

Hydropower is a potential large source of electricity supply in Wales. The Upper River Severn in Mid Wales is a typical stream where a high head hydropower scheme could be developed and the river system at Plynlimon has some of the longest records for weather and flow in Wales. A microhydropower potential of 99 kW is demonstrated at Plynlimon and the potential impacts of climate change are simulated to assess the effects on flows and power outputs of such schemes under climate uncertainty. Based on UK Climate Projections 2009 (UKCP09) projections, the impacts of climate change are to significantly decrease both the stream flows and energy production during summer months but to increase flows and power production in the winter, with a net tendency to cancel out over the course of a full year. A methodology for assessing impacts of climate change on hydropower is established, which could be applied more widely to other potential hydropower sites such as lowland rivers or high base flow rivers in other parts of the UK. This will be useful for developers, water companies and environmental agencies to assess hydropower potential, economic viability and environmental impacts of micro-hydropower, under future climate change. doi: 10.2166/nh.2012.012 s://iwaponline.com/hr/article-pdf/44/3/495/370465/495.pdf D. Carless (corresponding author) Southern Hydropower, King William House, London Road, Blewbury, Oxfordshire OX11 9PD, UK E-mail: dave@southernhydropower.co.uk P. G. Whitehead School of Geography and the Environment, University of Oxford, South Parks Road, Oxford OX1 3QY, UK

Precipitation, pH and metal load in AMD river basins: an application of fuzzy clustering algorithms to the process characterization

In the present work, Acid Mine Drainage (AMD) processes in the Chorrito Stream, which flows into the Cobica River (Iberian Pyrite Belt, Southwest Spain) are characterized by means of clustering techniques based on fuzzy logic. Also, pH behavior in contrast to precipitation is clearly explained, proving that the influence of rainfall inputs on the acidity and, as a result, on the metal load of a riverbed undergoing AMD processes highly depends on the moment when it occurs. In general, the riverbed dynamic behavior is the response to the sum of instant stimuli produced by isolated rainfall, the seasonal memory depending on the moment of the target hydrological year and, finally, the own inertia of the river basin, as a result of an accumulation process caused by age-long mining activity.

Presence of As in the fluvial network due to AMD processes in the Riotinto mining area (SW Spain): A fuzzy logic qualitative model

The Tinto River crosses the mining area of Riotinto (Iberian Pyrite Belt, SW Spain), where it receives the highest contribution of contaminants (AMD). In this paper we apply a fuzzy computer tool, PreFuRGe, which allows qualitative interpretation of the data recorded in a database relating to the chemistry of water. Specifically, we aim to find information not likely to be detected by means of classical statistical techniques, and which can help in characterizing and interpreting the behavior of arsenic in a complex system. The conclusions present that the factors which most directly control the presence of total dissolved As are closely linked to the climate and are temperature and rainfall, and therefore pH. As (III) is also shown to be related to temperature and pH. In terms of temperature As (V) is found to operate in a way which is the opposite of As (III). In terms of pH the relationship is not as clear as for As (III). As for rain, the highest As (V) values are compatible with minimum or non-existent rainfall, while minimum values correspond to any value for rainfall, including very high.

Characterisation of AMD Pollution in the Reservoirs of the Iberian Pyrite Belt

Abstract A number of water-supply dams have been built in the semi-arid Iberian Pyrite Belt (SW Spain) in a fluvial network affected by acid mine drainage (AMD). There are almost a hundred mines, most of which are closed, which emit low pH leachates with high metal and sulphate loads to reservoirs intended for urban supply. The Iberian Pyrite Belt contains 23 of these reservoirs spread along the Tinto and Odiel river basins, which are the main water courses affected by AMD, and the Chanza and the Guadiamar river basins, which are affected to a lesser extent. We characterised the degree of pollution in the various reservoirs that receive AMD-affected waters; this will eventually allow the development of a risk map of the overall extent of the problem in reservoirs in the Iberian Pyrite Belt.ZusammenfassungIm semi-ariden Iberischen Pyrit-Gürtel (Südwest Spanien), einem durch saure Grubenwässer (AMD) beeinträchtigten Flusssystem, wurde eine Reihe von Talsperren für die Wasserversorgung errichtet. Es gibt dort fast einhundert Bergwerke, zumeist stillgelegt, die Wasser mit niedrigen pH-Werten und hohen Metall- und Sulfatfrachten letztlich an Talsperren abgeben, die für die kommunale Wasserversorgung gedacht sind. Im Iberischen Pyrit-Gürtel gibt es 23 solcher Talsperren, verteilt in den Einzugsgebieten von Rio Tinto und Rio Odiel, die die durch AMD beeinträchtigten Hauptflüsse sind, und von Rio Chanza und Rio Guadiamar, die durch AMD weniger betroffen sind. Es wurde der Grad der Verunreinigung der verschiedenen Talsperren charakterisiert, die durch AMD beeinträchtigte Wässer erhalten. Das wird die Entwicklung einer Risikokarte für das Gesamtausmaß des Problems in den Talsperren im Iberischen Pyrit-Gürtel ermöglichen.ResumenDiques para suministro de agua se han construido en el cinturón pirítico ibérico (sudoeste de España) en una red fluvial afectada por drenaje ácido de minas (DAM). Casi un centenar de minas, la mayoría cerradas, producen lixiviados de bajo pH y con alta carga de metales y sulfatos que llegan a reservorios destinados para suministro urbano. El cinturón pirítico ibérico contiene 23 de estos reservorios a lo largo de las cuencas de los ríos Tinto y Odiel que son los principales cursos de agua afectados por el DAM, y las cuencas de los ríos Chanza y Guadiamar que son afectados en menor extensión. Hemos caracterizado el grado de contaminación en varios reservorios que reciben las aguas afectadas por DAM; esto eventualmente permitirá el desarrollo de un mapa de riesgo sobre la extensión global del problema en los reservorios del cinturón pirítico ibérico.抽象伊比利亚黄铁矿带(Iberian Pyrite Belt)位于半干旱的西班牙西南地区,沿该区河网修建了大量市政供水水坝。河网内河水已为酸性废水(AMD)污染,100多个矿井(多数已经关闭)将富含金属和硫酸盐的酸性废水最终排向了供水水库。在伊比利亚黄铁矿带内,Tinto和Odiel流域的23个水库受酸性废水(AMD)污染严重,而Chanza和Guadiamar流域水库受酸性废水污染较轻。评价了伊比利亚黄铁矿带内各水库的酸性废水(AMD)污染程度,绘制了水库的污染风险评估图。

Enrichment of trace elements in the clay size fraction of mining soils

Reactive waste dumps with sulfide minerals promote acid mine drainage (AMD), which results in water and soil contamination by metals and metalloids. In these systems, contamination is regulated by many factors, such as mineralogical composition of soil and the presence of sorption sites on specific mineral phases. So, the present study dedicates itself to understanding the distribution of trace elements in different size fractions (<2-mm and <2-μm fractions) of mining soils and to evaluate the relationship between chemical and mineralogical composition. Cerdeirinha and Penedono, located in Portugal, were the waste dumps under study. The results revealed that the two waste dumps have high degree of contamination by metals and arsenic and that these elements are concentrated in the clay size fraction. Hence, the higher degree of contamination by toxic elements, especially arsenic in Penedono as well as the role of clay minerals, jarosite, and goethite in retaining trace elements has management implications. Such information must be carefully thought in the rehabilitation projects to be planned for both waste dumps.

Statistical Contrast Analysis of Hydrochemical Parameters Upstream of the Tidal Influence in Two AMD-Affected Rivers

The Iberian Pyrite Belt (IPB), SW Spain, has been exploited since ancient times, and previous studies have compared different parameters in the Tinto and Odiel Rivers, the principal rivers that cross the IPB. We used classical statistics to draw contrasts between the two rivers. Samples were collected at two sites, one in the Tinto River, and the other in the Odiel, immediately upstream of tidal influence. Both rivers are strongly contaminated by acid mine drainage (AMD). However, the results suggest a distinctive, although somewhat parallel, geochemical behavior. The pattern of affinity between parameters differs because in addition to AMD, the Odiel River receives important contributions from non-contaminated catchments, while the Tinto River is the main receptor of drainage from the Rio Tinto mine. The applied statistical approach revealed that pH and electrical conductivity present a similar temporal evolution, which point to an identical geochemical signature; this indicates that both systems are similarly affected by contamination from the same pyritic area.ZusammenfassungDer Iberische Pyrit-Gürtel (Iberian Pyrite Belt, IPB) in Südwest-Spanien wird seit historischen Zeiten bergbaulich genutzt. Schon viele Untersuchungen beschäftigen sich mit Parametervergleichen zwischen den Hauptvorflutern im IBP, dem Rio Tinto und dem Rio Odiel. Wir nutzen klassische statische Methoden, um Unterschiede zwischen beiden Flusssystemen aufzuzeigen. Beide jeweiligen Untersuchungsstandorte im Rio Tinto und im Rio Odiel befanden sich oberstromig des Gezeiteneinflusses. In beiden Flüssen ist ein Einfluss vom AMD nachweisbar. Jedoch können an den Untersuchungsstandorten jeweils charakteristische und z. T. parallel verlaufende geochemische Verhältnisse erkannt werden. Die Ähnlichkeit zwischen den gemessenen Parametern differiert aufgrund des unterschiedlichen AMD-Einflusses. Während dem Rio Odiel maßgebliche Anteile aus nicht kontaminierten Einzugsgebieten zufließen, ist der Rio Tinto der Hauptvorfluter für Abflussanteile der Rio Tinto Bergwerke. Die statistische Auswertung macht deutlich, dass die pH-Werte und die elektrischen Leitfähigkeiten zeitlich ähnliche Entwicklungen aufzeigen und somit auf identische geochemische Signaturen hinweisen. Dieses zeigt, dass beide Flusssysteme durch die gleiche Pyritzone beeinflusst werden.ResumenLa faja pirítica ibérica (IPB), SO España, ha sido explotada desde tiempos remotos; estudios previos han comparado diferentes parámetros en los Ríos Tinto y Odiel que son los principales ríos que atraviesan la IPB. En este trabajo hemos usado estadística clásica para mostrar los contrastes entre los dos ríos. Las muestras fueron colectadas en dos sitios, uno en el Río Tinto y el otro en el Río Odiel inmediatamente río arriba de la zona de influencia de las mareas. Ambos ríos están fuertemente contaminados por AMD. Sin embargo, los resultados sugieren un diferente, aunque en alguna medida semejante, comportamiento geoquímico. El patrón de afinidad entre parámetros difiere porque el Río Odiel recibe importantes contribuciones desde afluentes no contaminados mientras que el Rio Tinto es el principal receptor del drenaje proveniente de la mina Río Tinto. La aproximación por estadística aplicada reveló que el pH y la conductividad eléctrica presentan una evolución temporal similar, que señala idénticas características geoquímicas; esto indica que ambos sistemas están afectados en forma similar por la contaminación proveniente de la misma área pirítica.抽象西班牙西南部的伊利比亚黄铁矿带(IPB)开采历史悠久,以往研究曾对比了横穿伊利比亚黄铁矿带(IPB)的Tinto河与Odiel河的水化学参数。本文采用传统统计学方法对比了两条河流水的水化学特征。研究分别于Yinto河与Odiel河受潮汐影响的上游取样。这两条河流都被酸性矿井水严重污染。但是,两种水样却显示出一种明显不同却有点类似的地球化学行为。由于除了AMD之外,Odiel河还接收大量未受污染流域来水,Tinto河水主要源于Rio Tinto矿井排水,两水样水化学参数之间关系明显不同。应用统计学的方法揭示,pH值和电导率呈现相似的时间演化过程,两水样具有相同的地球化学特征,表明两条河流经受着同一黄铁矿区的污染。

Hydrochemical characterization of an acid mine drainage-affected reservoir: the Sancho Reservoir, Huelva, southwest Spain

Abstract The objectives of this study were to discover the relationship between variables in a water reservoir and the hydrochemical variations related to acid mine drainage (AMD), and to describe the horizontal stratification related to vertical salinity and variations in metals present in the region. The information obtained may be used for establishing risk evaluation criteria and to design future remediation strategies, which could be useful for new dams. The hydrochemical characterization was based on a sampling campaign performed in October 2011. A total of 28 samples, at 1-m-deep intervals, were obtained. The hydrogeochemical study of the polluted reservoir shows that the dilution effect is not sufficient to neutralize AMD contributions from mining activity. Sampling carried out from the surface water to the deepest points reveals stratification of the reservoir that allows it to be included in the group of monomictic and holomitic lakes. Editor D. Koutsoyiannis; Associate editor M.D. Fidelibus Citation Cerón, J.C., Grande, J.A., de la Torre, M.L., Borrego, J., Santisteban, M., and Valente, T., 2014. Hydrochemical characterization of an acid mine drainage-affected reservoir: the Sancho Reservoir, Huelva, southwest Spain. Hydrological Sciences Journal, 59 (6), 1213–1224. http://dx.doi.org/10.1080/02626667.2013.834341